Today in the household appliances industry, the customers' demands for better appliances are increasingly bigger and more demanding, requiring more modern and esthetical designs, which are state-of-the-art and provide an added value, so they allow performing some of the domestic chores in an easier, safe and dependable manner, providing comfort and speed while performing these chores.
Among household appliances, and more particularly white goods, the washing machine is one of the household appliances considered as essential, as it is used for washing clothes, bedding and laundry in general, thus saving time and effort, but above all, what is sought for today is to be increasingly more environment-friendly, mostly saving in the greatest water consumption, using less detergent, optimizing wash cycles and therefore, consuming less power.
Currently, a broad range of washing machines exists, such as industrial, domestic, vertical (top loading), horizontal (front loading), automatic, semiautomatic, manual, drum, driver, agitator, and with spinning, among others.
Depending on the type of washing machine, different washing systems exist, namely:
i) European or front load system, which uses a drum that spins first in one direction carrying the clothes with it, and when they reach the top part, they fall on the water's surface. It pauses briefly for the detergent to act, and restarts the operation in the contrary direction. This continuous action received by the clothes when falling on the water is what finally separates dirtiness. The disadvantage of this system is that it requires longer wash cycles and, therefore, more power consumption.
ii) The American or top-loading system, which uses a central agitator with vanes that moves the clothes within the drum in a back and forth manner, where said agitator, additionally to “agitating” the water, rubs the clothes to separate dirtiness. This system produces a premature wear of the clothes, as the damage to the clothes is greater than in the other systems, additionally to requiring a high water consumption.
iii) Oriental or turbine system, which uses a turbine or pulser which is nothing more than a disc on the bottom of the tub with small vanes that, when rotating in different directions and at a great speed, generate a turbulence in the water, twisting the clothes, moving them up and down and rubbing them against each other and against the vanes and walls of the tub. This washing system is very aggressive for the clothes due to the friction on which this washing system is based in order to remove dirtiness, additionally to requiring a high water consumption.
iv) Infusor washing system, this system is the newest, which uses an infusor that generates water currents which removes the dirtiness in the clothes without need to apply friction between the clothes. The infusion technology washing machines push the water through the sides of the tub towards the center, while the infusor pushes the water towards the tubes walls, where the combination of this actions creates the water pressure that pushes the clothes through the washing machine for cleaning. The infusor operates because the water pressure causes the clothes to rub against each other and move through the water in order to remove the dirt particles with a much smaller amount of water than other systems.
Additionally to the aforementioned, it is well known that conventional automatic washing machines have in common the excessive water consumption, using 120 or more liters in a single load, where water usage is not maximized and a great waste of this precious liquid is generated. Similarly, they use a propeller or agitator system which, due to its form, needs a great amount of water, as they require a high water level in the drum in order perform the washing action. In this way, using a greater amount of water, conventional automatic washing machines achieve an even washing, as the water level is always higher than the level of the load to be washed, due therefore the homogeneity of the load washing is achieved in a somewhat rustic manner, generating an excess in the used water level, which is wasted at the end of the cycle.
Additionally, every washing machine is designed for cleaning textiles in a sequential manner by means of a washing cycle, a rinsing cycle and a spinning cycle. These cycles can be repeated according to the user's selection, the more the cycles are repeated, better cleaning of said textiles is obtained, having as a disadvantage the excessive water usage in order to obtain better results.
This is the case of the United States Patent Application US2001/0131734 A1, Kim et al., referring to a washing method in which the textiles cleaning is achieved by means of a water current, the manner in which this water current is generated is by spinning an inner tub, in a way such that the contained water rises through a space between the outer and inner tubs and falls into the inner tub on the clothes being washed; and the formation of an agitation water current by means of the rotation of the pulser. The forming of the first agitation water current can be performed several times and the formation of the second agitation water current is performed in the process of formation of the first agitation water current. Nevertheless this system has the disadvantage of continuously using the motor for spinning the tub and the pulser for generating the water currents, which generates a greater power consumption, and additionally the water level must be high in order to perform the current generation process for textile washing.
The U.S. Pat. No. 7,263,862 B2, Lyu, et al., describes a method by agitation washing generated by the inner tub and a pulser's rotation movement in the same direction at the same speed, where subsequently in a first time period an inner tub and the pulser rotate in a first direction and where in a second predetermined time period they rotate in a second direction opposed to the first direction. These movements force or push the textiles against an inner tub's wall and force the wash water in the inner tub to pass through the textiles and subsequently pass through the holes provided towards the outer tub, and to flow upwards through a space provided between the inner tub and the outer tub in a manner such that the water is recirculated into the inner tub. Nevertheless, this washing method rotates the inner tub and the pulser always in the same direction.
In turn, the U.S. Pat. No. 7,376,997 B2 describes a rinsing control method for a washing machine with a smaller amount of wash water, by means of the movement or rotation of the inner tub at a relatively high speed. Additionally, the rotation direction of the inner tub in the different wash steps of this patent can be contrary to the rotation direction of the first stage. Additionally, this invention includes a stage in which water is stored in the outer tub and at the same time rinsing or bleaching water is continuously supplied. As described by this patent, the washing of the textiles is performed by means of centrifugations generated by rotary movements of the inner tub.
Additionally, the U.S. Pat. No. 7,017,217 B2 describes a method of the washing machine rinsing cycle, which comprises the rotation of a tub at a first rotation speed, while water is sprayed into the tub, where a sufficient water level is reached according to the textiles quantity; it starts spinning at a second speed, which is higher than the first. In this patent, an oscillatory motion is generated by means of an agitator in order to achieve the washing of the textiles, subsequently the rinsing cycle is started, which uses the water rotation or centrifugation for removing the detergent from the textiles in an efficient manner without a conventional immersion rinsing and additional agitation. In this way, the rinsing water recirculation within the tub and the associated energy consumption are avoided.
The U.S. Pat. No. 6,668,410 B2 describes a complete washing method for a washing machine, which comprises the washing, bleaching or rinsing and dehydration cycles where the washing and bleaching cycles are generated by means of the rotation of the inner tub in one direction. In one penetration washing embodiment, when the pulser and the inner tub are rotated at a high speed, a centrifugal force is generated for pushing the clothes in the inner tub against a wall of the inner tub, and for pushing the wash water in the inner tub into the outer tub through the wash holes in the inner tub, when the wash water penetrates through the textiles said washing is generated. When the wash water is pushed out towards the outer tub, the wash water is pumped towards the top part of the outer tub along a space between the inner tub and the outer tube due to centrifugal force, until the wash water hits the tub's cover and is redirected again towards the inner tub. The wash water has an essentially high pressure while passing from the inner to the outer tub caused by the centrifugal force from the inner tub's high speed rotation. This high pressure and the water hitting effect when falling again into the inner tub due to gravity provide the washing. In other embodiment of this invention known as agitation washing, it is provoked by the setting of the rotation speed below a certain level. That is, if the motor rotation speed is adjusted to be comparatively low, the pulser and the inner tub also rotate at a low speed, where the generated centrifugal force will be unable to push the wash water upwards between the inner tub and the outer tub for maintaining a certain level. The textiles descend to the bottom part of the inner tub to be submerged in the wash water. Under these circumstances, the circulation of the wash water caused by the rotation of the inner tub and the pulser make the agitation washing easier.
According to the aforementioned, it is easy to identify and observe a great diversity of machines and methods existing in the state of the art for textiles washing, which generally use vanes or propellers in combination with the drum or tub motion in order to achieve agitation and/or water currents which move the clothes, thus generating the clothes rubbing mechanical action, this mechanical action produces the rubbing or friction between the textile garments additionally to the vanes or propellers, which damages the garments. Therefore, a need still exists in the art for textiles washing processes that do not damage the textiles, use the smallest amount of water in the washing processes and do not consume excessive energy due to the usage of the motors needed in order to achieve the wash tubs rotation needed.